Absorption refrigerating system



Nov. 7, 1939. c. c. cooNs ABSORPTION HEFRIGERATING SYSTEM Filed Nov. l3, 1935 2 Sheets-Sheet 1 III II INVENTOR Our-Zia 6. Goans Nov. 7, 1939. c. c. COONS 2.178.560

I ABSORPTION REFRIGERATING SYSTEM Filed Nov. 13, 1955 2 Sheets-Sheet 2 INVENTOR ATTORNEY atented Nov. 7, 1939 PATENT OFFICE ABSORPTION REFRIGERATING SYSTEM Curtis 0. Coons, North Canton, Ohio, assignor to 4 The Hoover Company, North Canton, Ohio, a

corporation of Ohio Application November 13, 1935, Serial No. 49,449

30 Claims.

This invention relates to continuous absorption refrigerating apparatus and more particularly to that type in which an inert gas is employed and in which-a compound or two stage boiler is used.

In accordance with the present invention, the compounding of the boiler system is accomplished in various ways, and a new boiler construction is provided so as to effect certain improvements in operation and efi'iciency or otherwise vary the operating conditions of refrigerating apparatus having compound boiler system.

Accordingly, it is one object of the invention to provide an absorption refrigerating apparatus with a novel compound boiler system.

It is another object of the invention to provide an improved boiler structure adapted for use in, an absorption refrigerating system, using inert gas and of the compound type.

It is another object of the invention to pro- .vide means for maintaining the proper temperatures in both the main boiler and the auxiliary boiler of the compound boiler system adapted for use in an absorption refrigerator.

Other objects and advantages reside in .certain novel features of the arrangement and construction of parts as will be apparent from the following description taken in connection with the accompanying drawings, in which Figure l is a diagram of a continuous absorption refrigerating system constructed in accordance with one embodiment of the invention, certain of the parts being cut away to better illustrate the construction;

Figure 2 is a vertical cross sectional view of a fragment of the absorber used in the arrangement of Figure l and showing the construction of a liquid seal incorporated therein;

Figure 3 is a vertical cross sectional view of the pumping means employed in the arrangement of Figure l.

Figure 4 is a transverse cross sectional view of the liquid pumping means shown in Figure 3, the view being taken on the line 44 of Figure 3,

Figure 5 is a vertical cross sectional view of the boiler system used in the arrangement of Figures 1, 6 and '7;

Figure 6 is a diagram of a continuous. absorption refrigeration system illustrating another embodiment of the invention, a portion of the absorber being cut away to show the internal construction,

Figure 7 is a diagram of still another embodiment of the invention, one of the parts being cut away to show the internal construction,.

Figure 8 is a vertical cross sectional view of the absorber used in the arrangement of Figure 7, and

Figure 9 is a diagram of still another embodiment of the invention, certain of the parts being cut away to show the internal construction.

Referring to the drawings in detail, and first to the arrangement of Figure 1, it will be seen that a continuous absorption refrigerating apparatus has there been illustrated. This apparatus includes a condenser C, an evaporator E, an absorber system, which in reality consists of two absorbers A1 and A2, a boiler system which in reality consists of two boilers B1 and B2, a rectifier R. and pumping means marked P, together with various conduits interconnecting these parts as shown to form the complete system.

The boiler system is shown in detail and enlarged in Figure 5. In constructing this boiler system, three concentric sections of pipe marked M, 2, and I3, are welded to end plates of annular shape, marked M and I5. Each of the plates l4 and i5 has a central opening through which the central pipe H passes so that the inside of the pipe It acts as a flue for the heating of the boiler, suitable heating means, such as a gas flame l6 being provided therein.

The boiler B1 is formed by the concentric pipes H and I2 and the end plates I4 and [5. This boiler is thus simply an annular chamber immediately adjacent'the heating flue H. The lower end of the boiler B1 is connected to the top of the boiler B2 by means of a conduit l1 which passes through the upper part of the pipe section l2 and is preferably provided with a slight hook at its upper end. The conduit I1 is not a vapor lift pump, but is simply a means for conveying liquid from the lower part of the boiler B1 to the top of the boiler B2. If desired this conduit may pass outside of the boiler E1, the arrangement illustrated being desirable, however, in that it provides a more compact assembly.

The boiler B2 is formed by the pipes l2 and I3 and the endplates l4 and IS. The outer boiler B2 is intended to have inert gas therein and it is intended that refrigerant vapor be generated from absorption liquid therein into the inert gas. In order to facilitate this action, a number of baflle plates l8 are provided in the holder chamber B2, these baflie plates having openings l9 therein arranged in staggered relation on opposite sides'of the chamber. It

will be understood that the baffle plates i8 are annular in shape, like the boiler B2.

- The main boiler B1 is connected to a rectifier R by means of a conduit 2| welded to its upper end. The top of the rectifier R is connected to the condenser C by the conduit 22, this conduit being like that in any continuous absorption refrigerating system for conveying refrigerant from the rectifier to the condenser. As the refrigerant condenses in the condenser C it flows through the conduit 23 into the evaporator E. The evaporator may be of conventional construction and have a number of battle plates therein for causing the refrigerant supplied thereto to evaporate into inert gas therein.

The absorber system may be similar to that disclosed in the co-pending application of Rudolph S. Nelson, Serial No. 37,711 filed August 24, 1935, and entitled Absorption refrigerating apparatus. As shown in Figure 1, it diflers slightlyin that it has a fan 24 mounted in the upper end thereof, and adapted to be driven by an electric motor 25. By means of a central partition 26, the cylindrical vessel which forms the two absorbers A1 and A: is divided into two chambers. As shown in Figure 2, the partition 26 is provided with means for allowing liquid to pass from the upper absorber Ar into the lower absorber A: through the U-shaped liquid conduit 21 which acts to provide a liquid seal. The lower end of the .U-pipe 2'! is disposed around a downwardly depending nipple 26 on the plate 26, so that in case a material diiIerence in pres sure exists between the absorber sections A1 and A: gas may pass through the nipple 28 when the pressure becomes sufllcient to break the seal of liquid formed in the liquid conduit 21.

In addition to the dividing partition 26 both sections A1 and A: of the absorber system are provided with a number of baflie plates 29 for providing an extended surface therein which aids in bringing the absorption liquid and the gas to be absorbed into intimate contact. Each of the plates 29 is provided with an offset openin: 39, these openings being staggered in the absorber so as to cause the-liquid to flow in a tortuous path therethrough.

The upper absorber A1 is connected to the evaporator by means of two inert gas conduits 3| and 32, portions of these conduits preferably being in heat exchange relation as illustrated. The conduit 3| connects the top of theevaporator to the bottom of the absorber A1 while the conduit 32 connects the top of the absorber A1 to the bottom of the evaporator. Circulation of inert gas between the evaporator and the absorberA1- is caused by the fan 24-which discharges directly into the conduit 32 at the point where it is connected to the absorber A1. Other gas circulating means may be employed without departing from the spirit of the invention.

A second inert gas circuit is provided between the absorber section A: and the auxiliary boiler B2. For this purpose an inert gas conduit 33 is connected to the top of the absorber A: and to the bottom ofthe boiler B2. A second gas conduit 34 connects the top of the boiler 13: to the fluid circulating pump P. which is in turn connected to the lower part of the absorber A: by meansof the conduit 35. It will be noted that the point of connection of the conduit 35 to the absorber A: is such that the lower portion of the absorber A: may act as a reservoir for liquid.

Absorption liquid is circulated between the boiler system and the absorber system by means into the pump chamber proper.

of the fluid circulating device P. For this purpose a liquid conduit 36 is connected to the bottom of the auxiliary boiler B2 and to the pumping device P. From this pumping device the conduit 31 conveys the absorption liquid to the top of the absorber A1 and from there the absorption liquid flows by gravity downwardly through the absorber A1, the liquid trickling over the baiile plates therein. It then flows through the liquid conduit 21 and on to the baille plates in the absorber section A2. After trickling downwardly over this set of baiile plates, the absorption liquid flows by gravity through conduit 34, a portion of which may be in heat exchange relation with the conduit 36 as illustrated, and into the rectifier R or, if desired, directly into the boiler B1. Since the rectifier is connected to the boiler B1 by the conduit 2|, liquid supplied to the rectifier may fiow downwardly through this pipe into the boiler section B1 where it is heated and refrigerant generated therefrom. The liquid then fiows from the boiler B1 into the boiler B: through the conduit H as mentioned above.

The liquid and gas pumping device P is shown in detail in Figures 3 and 4. It consists of a cylinder 39 disposed in an inclined position with an electric motor 4| mounted on the upper end thereof. The motor drives a shaft 42 which is mounted in suitable hearings supported on end plates 43 and 44. The liquid pumping portion may be like that disclosed in my co-pending application Serial No. 55,449 filed December 23, 1935. The arrangement here shown consists of means for forming a centrifugal pump chamber with a rotor therein. Two plates or housing members 40 and 45 are secured in spaced relation by an annular ring 46 and bolts 41 to form the chamber. The shaft 42 extends centrally through this chamber and has a rotor 48 carried thereby. The rotor 46 is so cut as to provide a number of blades 49. The liquid enters the pump chamber through a small opening 56 in the plate and near the lower end thereof. Liquid leaves the chamber through an opening 5| in the annular spacer ring 46, the opening 5| being arliquid from the boiler B2 to the pump P is connected to the lower side of the cylinder 39 so that the liquid can readily flow from the space above the plate 45 through the opening 50 and The discharge conduit 31 is connected to the pump chamber in line with the discharge opening 5| as shown in Figure 4.

The upper portion of the cylinder 39 contains a fan 52 for circulating the inert gas between the boiler B1 and the absorber A2. As best shown in Figure 3 the inert gas supply conduit 34 is connected to the cylinder 39 at a point near the top thereof, above a plate 53 which has an opening in. the central portion thereof to provide a fan eye adjacent the rotor 52. Likewise, the gas discharge conduit 35 is connected to the cylinder 39 at a point opposite that of the location of the rotor 52 so that as the rotor revolves gas is blown into the conduit 35 by centrifugal action. A plate 54 is provided immediately beneath the fan 52 so as to co-operate with the plate 53 to provide a fan chamber.

For conducting any liquid which mayfind its way into the fan chamber the U-shaped conduit- 55 is provided, and connected to the lower portion of the fan chamber and to the cylinder 39 below the point of connection of the conduit 36.

The directions of flow of the fluids in the system are indicated, solid arrows showing direction of flow of the liquids and .dash arrows showing the gases. Assuming that the system is charged with water as absorbent, ammonia as refrigerant, and

. nitrogen as inert gas and that after it is charged in accordance with known practices it is hermetically sealed, a number of cycles of fluid circulation will be set up when heat is applied to the boiler and when the motors 25 and 4| are energized.

Starting with the boiler B1, the ammonia will pass through a cycle which may be called its main cycle in which it will be vaporized in the boiler B1, flow throughv the conduit 2i, the rectifier R and the conduit 22 as vapor, be condensed in the condenser C, evaporated in the evaporator E and pass with the nitrogen through the conduit 3| into the absorber A1 where it will be absorbed in the aqueous solution therein, flow through the liquid conduit 21, downwardly through the absorber A2, through theconduit 38, the rectifier,

and thence through the conduit 2| back into the boiler B1.

At the same time the ammonia will pass through a second cycle in which the ammonia will be generated and absorbed. Starting from the boilerBz the ammonia will be vaporized from the solution into the nitrogen in the boiler B2 and flow through the conduit 34, the pump P and the conduit 35 into the absorber A2 where it will be absorbed out of the nitrogen by the solution passing downwardly through the absorber A2 and returned to the boiler B2 through the conduits 38, the rectifier R, the conduit 2!, the boiler B1 and the liquid conduit l I.

At the same time the water or absorption solution will be caused to circulate from the boiler B2 through the conduit 36, the pump P and the conduit 31 into the top of the absorber A1. After trickling downwardly over the bafie plates in the absorber A1 it will pass through the liquid conduit 2i and downwardly over the baiile plates in the absorber A2. It then flows back to the boiler B1 through the conduit 38, the rectifier R, and the conduit 2i, and from the boiler B1 it returns to the boiler 32 through the conduit ll. Conduit 2! should be large enough that the vapor may flow up and the solution down without interference with each other therein. In the boiler B2 the solution trickles downwardly over the bafile plates l8 and again enters the conduit 35 to complete the cycle.

At the same time two inert gas circuits are set up, one being induced by the fan 25 and consisting of a path between the absorber A1 and the evaporator E, through the conduits 3i and 32 as described above, while the other is induced by the fan 52 and includes the absorber A2, the boiler B2, and the conduits33, 3d and 35.

In a compound boiler system, the main boiler is normally maintained at a higher temperature than the auxiliary boiler. Inert gas is not intentionally present in the main boiler but is circulated through the auxiliary boiler. The boiler arrangement shown in Figure 5 is so constructed as to maintain the proper temperatures and heat inputs to the boilers. The construction is such that heat is transferred from the source in the flue I I first to the liquid in the boiler B1 and then to the liquid in the boiler B2. By properly proportioning the areas of contact the proper gradient in temperature between the boilers B1 and B2 can be maintained. At the same time, if the boiler B2 is at a lower temperature and surrounds the boiler B1 an economy in heat losses is effected, since the boiler B2 acts as an insulation to some extent around the boiler B1.

A compound refrigerating system in which two boilers are used but in which there is only one inert gas circuit, may be constructed in accordance with the present invention, as shown in Figure 6. ,In this embodiment the boiler construction may be identical to that shown in Figures 1 and 5. Likewise the rectifier, the con denser, the evaporator, and the pump may be the same and these elements are designated the same as the corresponding parts in Figure 1. Likewise the conduit which connects the boiler B to the rectifier is designated 2|, the conduit connecting the rectifier to the condenser 22, the conduit connecting the condenser to the evaporator 23, While the liquid conduits 36, 31 and 38 which may be identical in construction and function to those previously described in connection with Figure 1 have been similarly designated.

The absorber A of Figure 6 consists merely of a plain cylindrical vessel in which a number of bafile plates 56 are provided, these baflie plates having openings 51 therein arranged in staggered relation. The lower part of the absorber may act as a reservoir for liquid.

An important feature of Figure 6 is the arrangement of the inert gas circuit. A gas conduit 58 connects the bottom of the evaporator E to the top of the absorber A. A second inert gas conduit 59 connects the bottom of the absorber A to the top of the boiler B2. A third inert gas conduit 60 connects the bottom of-the boiler B2 to the pump P, and a fourth inert gas conduit 6i connects the pump P to the top of the evaporator E. With this construction the evaporator, absorber, boiler B2 and pump" are all connected in series in so far as the inert gas circuit is concerned, the inert gas flowing downwardly from the top of the evaporator through the conduit 6!, thence through the pump P, the conduit 60, upwardly through the boiler section B2, andthence through the conduit 53, the absorber, and back to the evaporator through the conduit 58.

While the inert gas is circulating as described above in the arrangement of Figure 6, the refrigerant may be caused to pass through two cycles, one being from the boiler B1 through the conduit 2!, the rectifier R, the conduit 22, the condenser C where the refrigerant is liquefied, the conduit 23, the evaporator E, where it evaporates to produce a cooling efiect and flows with the inert gas through the conduit 65, then through the pump P, the auxiliary boiler B2, and into the absorber where it will be absorbed by the absorption liquid and conveyed back to the boiler B1 through the conduit 38, the rectifier R, and the conduit 2!.

A second refrigerant cycle consists in the evaporation or generation of vapor in the boiler B2, its passage through the conduit 59 into the absorber where the vapor is absorbed and the return to the'boiler B2 through the conduit 38, the rectifier R, the pipe 20, the boiler Bi, and the conduit l1.

In'the arrangement of Figure 6 the absorption liquid circulates exactly the same as in the arrangement of Figure 1, and it will be unnecessary to repeat its cycle here.

An advantage of the arrangement of Figure 6 results from the fact that it is unnecessary to separate the absorber into two chambers. The

two inert gas circuits are combined and only one gas circulator is employed to circulate the gas through the various parts of the system in a single circuit. The arrangement of Figure 6 nevertheless provides means for gaining the advantages brought about by the use of the compound boiler. The refrigerant evaporates into the inert gas in the evaporator while this evaporator is at a low temperature. As the mixture of refrigerant and inert gas is conveyed through the boiler B2, additional refrigerant is evaporated into the mixture from the solution in the boiler B2, so that the mixture of gases flowing upwardly through the conduit 59 has a higher refrigerant content than that flowing downwardly through the conduit 6|. .If the absorber is adequately cooled, both the refrigerant which is evaporated in the evaporator and that which was generated in the boiler B2 may be absorbed in the absorption liquid so that as it flows downwardly through the conduit 38 it is relatively rich. As this rich absorption liquid flows through the boiler B1, the refrigerant is gene ated therefrom. In the boiler B2, the solution which has been weakened in the boiler B1 is further reduced to a lower refrigerant content, even though this vessel is at a lower temperature, since there is inert gas in the boiler B2. The solution which flows from the boiler B: through the conduit 36 back to the absorber is thus brought to a very low degree of concentration so that as it comes in contact with the mixture of inert gas and refrigerant in the upper part of the absorber" it may reduce the refrigerant content in the inert gas passing back to the evaporator through the, conduit 58 to a very low degree.

It will be clear from what has been said above that in the arrangement of Figure 1, two separate inert gas circuits are provided, while in the arrangement of Figure 6, a single inert gas circuit .is provided in a compound system. In accordance with still other embodiments of the invention, it is possible to devise inert gas circuits in which the evaporator, the absorber, and the auxiliary boiler'are in series but in which the circuit to the auxiliary boiler is by-passed or shunted to a certain extent, so that more inert gas may circulate between the evaporator and the absorber than circulates between the evaporator, absorber and auxiliary .boiler. Arrangements of this sort are shown in Figures '7 to 9.

In the arrangement of Figure 7 the boiler system, the rectifier, the condenser, and the evaporator are the same as that described in connection with Figures 1, 3, 4, 5 and 6 and are similarly designated. In this figure, the absorber is combined with the liquid and gas circulator into one structure, the arrangement being the same as that shown in Figure 11 of the co-pending application in the name of Curtis C. Coons and Arnold D. Siedle, entitled Absorbers for refrigerating systems, Serial No. 23,628, filed May 27, 1935.

The main part of the absorber is shown in enlarged cross section in FigureB. It may consist of a cylindrical vessel 62 having a number of baiile plates 63 therein each of which is provided with an opening surrounded by a depending flange 64. An electric motor 65 is mounted on the upper end of the vessel 62 and is adapted to drive a Shaft 66 which extends longitudinally through it. The shaft carries a fan 61 near its upper end, and a number of agitators or splash ing devices 68 at spaced points along its length, there being one splashing device 68 beneath each of the depending flanges 64 on the baflie plates 63. Each splashing element is cup shaped as shown in Figure 8 so that the liquid which passes through the baiile plates 63 falls upon the inside of the splashers 68 and is thrown outwardly and around the interior surface of the vessel 62 as it travels downwardly through the absorber. The lower end of the shaft 66 carries a rotor 69 of a liquid pump which may be similar to that shown in Figure 4. The rotor is positioned between the end plate 18 of the absorber vessel and a plate H on the inside thereof, these plates cooperating to form a pump casing. The absorption liquid flowing down through the absorber vessel passes through a small opening 12 in the lower part of the plate H and is thrown outwardly through an outlet conduit connected to the vessel as will presently be described.

In addition to the main part 62 of the absorber,

in the arrangement of Figure 7, there is an auxiliary absorber vessel13, located some distance above the main vessel 62. The main vessel 62 is connected to this auxiliary vessel 18 by means of a liquid conduit 14 this conduit being connected to the lower part of the absorber vessel opposite the location of the rotor 69 of the liquid pump so that it acts' as a discharge for this pump and conveys absorption liquid from the vessel 62 to the top of the vessel 13. From the vessel 13, the absorption liquid flows by gravity through the U-shaped pipe 15 into the rectifier R and from there through the conduit 2| to the main boiler B1 from which it flows through the conduit l1 into the boiler B2. After trickling downwardly over the baffle plates ,therein, the liquid necessary into the vessel 13, the excess may be returned to the absorber 62 through the overflow pipe 11. The conduit 11 may have a valve therein for controlling the flow of liquid thereeg through, if desired. Certain portions of the con duits 15 and 16 may be in heat transfer relation and this may also be the case in connection with the conduits l6 and I1.

Any inert gas which may find its way into the vessel 13 may be discharged therefrom into the inert gas circuit through the conduit 18 COnu nected to the inert gas system which will now be described.

The top of the absorber vessel 62 is connected to the bottom of the evaporator E by means of the inert gas conduit 19 while the top of the evaporator is connected to the bottom of the vessel 62 by the inert gas conduit 80, the conduits 19 and 88 being in heat exchange relation. At any convenient point in its path, the inert gas conduit 88 is provided with a restriction as shown at 8|, and the gas conduits 82 and 83 are connected on the opposite sides of this restriction to provide a connection to the lower and upper ends respectively of the auxiliary boiler B2. While a restriction is shown at 8|, in the arrangement of Figure 7, it is obvious that a valve or other variable means may be used to vary the size of the restriction at this point. After the proper size has been determined by experimentation, a permanent' restriction like that illustrated may be employed;

As shown in Figure 7, the gas conduits 82 and With the inert gas circuit constructed as described above, the inert gas may be caused to flow under the influence of the fan 61, driven by the motor 65 in the top of the vessel 62. The gas flows upwardly through the inert gas conduit19 into the evaporator downwardly through the conduit 88, the restriction BI, and into the bottom of the vessel 62, and then upwardly therethrough to complete its cycle. At the same time, the inert gas will flow from the fan 61 upwardly through the conduit I9, the evaporator E, the upper part of the conduit 88, the conduit 82, into the boiler B2, and after passing upwardly therethrough return to the absorber 62 through the conduit 83 and the lower part of the conduit 88. In the last mentioned inert gas circuit, the absorber 62, the evaporator E, and the boiler B2 are connected in series as in the arrangement of Figure 6, but a portion of the inert gas is bypassed around the boiler B2.

As in the arrangements of'Figures 1 and 6 the refrigerant in the arrangement of Figure 7 passes through two cycles. Some refrigerant is generated in the boiler B1. passes through the conduit 2I, the rectifier R, the conduit 22, the condenser C, the conduit 23, the evaporator, where it produces a cooling eifect, the inert gas conduit 88 and into the absorber 62 where it is absorbed, and flows back to the boiler B1 through the conduits 78 and I5, the rectifier R and the conduit 2I. At the same time, another amount of refrigerant is generated in the boiler B2, flows through the inert gas conduit 83, the lower portion of the conduit 88, into the absorber 62 where it is absorbed and flows back to the boiler B through the conduit I4, the vessel 13, the conduit I5, the rectifier R, the conduit 2|, the boiler B1 and the conduit I7.

Likewise, the arrangement of Figure '7 enables the absorption liquid supplied to the absorber to be brought to a low concentration, while that which leaves the absorber is at a high concentration, as in the arrangement of Figure 6. The absorption liquid flowing through the conduit I! after considerable refrigerant has been expelled therefrom in the main boiler B1, has its concentration further reduced in the boiler B2 so that that which leaves the boiler B2 through the conduit I6 has a very low concentration of refrigerant. It is thus possible to strip the inert gas flowing upwardly through the conduit I9 to the evaporator of its refrigerant content just before it leaves the absorber. On the other hand, the inert gas which enters the lower part of the absorber vessel 62 has a high refrigerant content,

since it has been enriched in the boiler B2. As this rich gas and absorption liquid come in contact in the lower part of the absorber 62, a high degree of concentration is reached and the liquid which flows through the conduits I4 and 15 back to the boiler system has a high concentration.

The advantage of the arrangement of Figure '7 over that of Figure 6 is that a proper degree of regulation of inert gas flow through the auxiliary boiler may be provided to obtain the best operating conditions.

An arrangement in which a compound boiler system employs an inert gas circuit similar to that described above in connection with Figure 7 is shown in Figure 9. In this figure, two absorbers are employed, and the two boilers B1 and B2 are separated although a single source of heat is employed to generate refrigerant in both of them.

In the arrangement of Figure 9, the boiler B1 may consist simply of a cylindrical vessel arranged in ahorizontal position and may be provided with a dome 84. A vapor lift pump conduit 85 is connected to the dome 84 and is adapted to convey liquid and refrigerant gas from the boiler B1 into a small gas separation chamber 86 located above the auxiliary boiler B2.

The auxiliary boiler B2 consists of'a vertically disposed cylindrical vessel having a flue 81 extending vertically thereto, and a number of baffle plates 88 therein. The gas separation chamber 86 is connected to the boiler B2 by a U-shaped conduit 89 forming a liquid seal.

The heating flue used to supply heat to the boiler B1 as shown at 98, has one end connected to a chimney 9i which passes up vertically and surrounds the auxiliary boiler B2. Thus when heat is supplied to the boiler B1 by a suitable source located in the heating tube 98, the gases of combustion or heated air may also pass upwardly through the chimney 9| and convey some heat to the auxiliary boiler B2, the flue 81 in the boiler B2 aiding in transferring the heat from the chimney gases to the boiler B2.

The gas separation chamber 86, located on the top of the boiler B2, is connected by means of a conduit 92 to a rectifier R, which is in turn connected by the conduit 93 to a condenser C adapted to feed liquified refrigerant to the evaporator through the conduit 94.

It should be noted that the gas separation chamber 88 is independent of the main portion of the boiler B2. There is no inert gas in the chamber 86.

Absorption .iquid pumped into the chamber 88 by the gas lift pump 85 flows through the liquid seal device 89, and trickles downwardly through the boiler B2. It then flows through the conduit 95 which connects the boiler B2 to the absorbers, there being a liquid divider or T-connection 96 to cause some absorption liquid to flow into the conduit 91 leading to the absorber A2 while another portion flows through the conduit 98 into the absorber A1.

The absorber A2 consists of a vertically disposed cylindrical vessel having electric motor 99 mounted on the top thereof, and adapted to drive a gas fan I88 which is located in its upper part. The fan causes circulation of inert gas to both of the absorbers A1 and A2, and also the evaporator E and the boiler B2 as will presently be described.

The absorption liquid supplied to the absorber A2 trickles downwardly over bafile plates I8I therein, and then flows into the lower part of the absorber A1 through the conduit I82 which has a U-bend therein to provide a liquid seal. The absorption liquid which flows into the absorber A1 through the pipe 98 trickles downwardly over baffle plates I83 therein and joins the absorption liquid entering this vessel through the conduit I82-and flows back to the boiler I through the liquid conduit I84. The conduits I84 and 95 maybe in heat exchange relation as illustrated.

The inert gas circuit of Figure 9 includes a gas conduit I85 connecting the top of the absorber A2 to the bottom of the evaporator E. A second inert gas' conduit I86 connects the top of the evaporator to the bottom of the absorber A1. This conduit has a restriction therein as shown at I81 and two inert gas conduits I88 and I89 are connected to thereto the opposite sides of the restriction, the conduit I88 being connected to the lower part of the boiler B2 and the conduit I89 connected to the upper part thereof. The conduits I88 and I89 are in heat exchange relation. In addition to the inert gas conduits men- Figure 9 are the same as those in Figure '7 except that the inert gas, rich in refrigerant, coming into the absorber system through theconduit I06, first passes in contact with comparatively strong solu--,

tion in the lower part of the absorber A1, and

then in contact with weaker solution in the upper part of the absorber A1, so that when it flows to V,

boiler operative to circulate fluid therefrom into the absorber A: through the conduit H0, the re,- irigerant content therein has already been materially reduced. As it passes upwardly through the absorber A2 in contact with the weak absorption liquid entering this vessel through the conduit 91, the inert gas is 'strippedor reduced to a low refrigerant content and then expelled from the absorber Az by means of the fan I00.

It will also be noted that there is no power driven liquid pump in the arrangement of Figure 9, the gas lift-pump 85 being used in place thereof. Except for the'use of two absorbers and the difierences in the boiler system and the liquid pumping means, the system of Figure 9 is similar to that of the other figures and can be readily understood by those skilled in the art, without repeating the paths for the flow of the fluids.

While only a few embodiments of the invention have been shown and described herein it is obvious that various changesimay be made without departing from the spirit of the invention or the scope of the annexed claims.

I claim: W

1. Compound absorption refrigerating apparatus using inert gas'and including an evaporator, an absorber, an inert gas charged boiler and means for circulating the inert gas in a circuit through said evaporator, boiler and absorber with more inert gas passing through the evaperator than through the gas charged boiler, the arrangement being such that refrigerant'is added to the inert gas in the evaporator, more refrigerant added to the inert gas in the boiler,and the refrigerant added to the inert gas both. in the evaporator and boiler removed therefrom in the absorber.

2. Compound absorption refrigerating apparatus using inert gas-and including an evaporator, an absorber, an inert gas charged boiler, inert gas conduits connecting the evaporator and the absorber, and means connected in parallel with a portion of one of said conduits for circulating inert gas through said' gas charged boiler.

3. Compound absorption refrigerating apparatus using inert gas and including an'evaporator, an absorber, an inert gas charged boiler, inert gas conduits connecting the evaporator and absorber,'one of said conduits having a restriction therein and gas conduits connecting the gas charged boiler to the conduit on the opposite sides of said restriction, the arrangement being such that some inert gas may flow in series between the evaporator, boiler and absorber while other gas flows between the evaporator and absorber by-passing the boiler.

4. Compound absorption refrigerating apparatus using inert gas and including an evaporator, two absorbers, an inert gas charged boiler, means for supplying weak absorption liquid to both absorbers, means for circulating inert gas through the evaporator the gas charged boiler and the absorbers in series, the arra g m n being such that there is provision for by-passing some gas around said boiler. W

5. In continuous absorption refrigerating apparatus, a boiler system comprising a heating flue, a boiler surrounding said heating flue and a second boiler surrounding said first mentioned boiler, the; arrangement being such that heat is transferred from said heatingflue to said first mentioned boiler and from said first mentioned boiler to said second mentioned boiler and means responsive to a high temperature in said first said second boiler.

6. In continuous absorption refrigerating apparatus using inert gas, a compound boiler system comprising a heating flue, a main boiler surrounding said heating flue, an auxiliary boiler surrounding said main boiler, means for circulating absorption liquid through said main boiler and said auxiliary boiler in series and in the order named and means for circulating inert gas through said auxiliary boiler.

7. In continuous absorption refrigerating apparatus, using inert gas, a compound boiler system comprising a'main boiler for generating a first body of refrigerant, means for discharging said refrigerant from the boiler system, an auxiliary boiler for generating a second body of refrigerant, means using a single source of heat for heating said boilers, means for circulating absorption liquid through said main boiler and said auxiliary boiler and means for circulating inert gas through said auxiliary boiler to remove said secondbody of refrigerant, the arrangement being such that heat is transferred from the source of heat to said main boiler and from said main boiler to said auxiliary boiler.

8. In continuous absorption refrigerating apparatus, a compound boiler system comprising three concentrically disposed cylinders having their ends ccnnectedby annular end plates so as to form two chambers concentrically disposed around a centrally located passage adapted to act as a heatingflue for transferring heat from a fluid therein to the inner concentric chamber and from the inner concentric chamber to the outer concentric chamber and means responsive to a high temperature in the inner of said chambers. and operative to transfer fluid therefrom to the outer of said chambers.

9. Compound absorption refrigerating apparatus using inert gas and including an evaporator, an absorber, an inert gas charged boiler, inert gas conduits connecting the evaporator and absorber afiording a circuit for the passage of gas through said absorber and evaporator in series, and means connected in parallel with a portion of said circuit for circulating inert gas through said gas charged boiler.

10. An absorption refrigerating apparatus containing a pressure equalizing gas and operating at three temperature ranges, namely, a relatively high temperature range of heat input, a relatively low temperature range of heat input and an intermediate temperature range of heat rejection, said apparatus including a plurality of vessels operating in said low and interemediate tem perature ranges, means affording a complete cycle of circulation of said pressure equalizing n absorption refrigeration system of the type 7 using a refrigerant, an absorbent therefor, and a pressure equalizing medium comprising applying heat to two bodies of rich absorbent in liquid communication, condensing the refrigerant liberated by one of said bodies, allowing said refrigerant to evaporate into a pressure equalizing me dium to produce refrigeration, conveying the mixture thus formed into contact with said sec-- ond body of absorbent whereby additional refrigerant is liberated and conducting the newly formed mixture into intimate contact with lean absorbent derived from at least one of said bodies whereby the refrigerant is absorbed.

12. The method of producing refrigeration in an absorption refrigeration system of the type using a refrigerant, an absorbent therefor, and a pressure equalizing medium comprising raising the temperature of two bodies of rich absorbent in liquid communication to liberate refrigerant, condensing the refrigerant from' one of said bodies, allowing said refrigerant to evaporate into a pressure equalizing medium to produce refrigeration, and passing the mixture so formed into intimate contact with lean absorbent after by-passing a portion of the mixture into contact with the other body of absorbent whereby additional refrigerant is liberated by said second body of absorbent, and substantially all the refrigerant liberated from both bodies is subsequently absorbed.

13. The method of reducing the concentration of the absorbent medium in the generator of an absorption refrigeration system which comprises applying heat to absorbent to liberate a medium contained therein, passing the partially deconcentrated absorbent into another zone, applying heat thereto without increasing the temperature of the absorbent, and passing an inertgas under pressure over the absorbent whereby the concentration of the absorbent is further reduced.

14. The method of reducing the concentration of the absorbent medium in the generator of a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and an inert gas, which comprises applying heat to the absorbent to liberate a refrigerant, passing the partially deconcentrated absorbent into the presence of the inert gas where additional refrigerant is liberated without increasing the temperature of the absorbent or reducing the total pressure in the system.

15. The method of reducing the concentration.

of the absorbent in the generator of a closed absorption refrigeration'system employing a refrigerant, an absorbent therefor, and an inert gas, which comprises applying heat to rich absorbent to liberate refrigerant and passing the partially deconcentrated absorbent into the presence of inert gas while maintaining the absorbent in heat exchange relation with said heated rich absorbent. whereby the concentration of the absorbent is further reduced in the presence of the relation with the heated absorbent whereby the concentration of the absorbent is further reduced in the presence of the same total pressure and at a lower temperature than would otherwise be possible.

17. The method of reducing the concentration of the absorbent in the generator of a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a pressure equalizing medium, which comprises applying the 10 heat of a burning flame to rich absorbent to liberate refrigerant, passing the partially deconcentrated absorbent into the presence of a pressure equalizing medium, and continuing to heat said last mentioned absorbent by the products of combustion from said flame whereby additional refrigerant is liberated in the presence of the same total pressure and without increasing the l temperature of the absorbent. 18. The method of reducing the concentration of the absorbent in the generator of a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and an inert gas, which comprises applying heat to rich absorbent to liberate refrigerant, passing the partially deconcentrated absorbent into the presence of an inert .gas, and liberating additional refrigerant into the inert gas by subjecting the last mentioned absorbent to waste heat from said first mentioned rich absorbent. I

19. The process of producing refrigeration in a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a pressure equalizing medium, which comprises applying heat to rich absorbent to liberate refrigerant, condensing the refrigerant, permitting frigerant is liberated, recombining the two portions of the mixture, then conducting the mixture into intimate contact with the lean absorbent whereby the refrigerant is absorbed, and

then returning the equalizing medium to the 45 evaporating zone and the enriched absorbent to the heating zone in order that the process may. be repeated continuously.

20. The process of producing refrigeration in a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a pressureequalizing medium, which comprises applying heat to rich absorbent to liberate refrigerant, condensing the refrigerant, permitting the refrigerant to evaporate into an equalizing 5 medium to produce refrigeration, conducting one portion of the mixture so formed over partially deconcentrated absorbent to liberate additional refrigerant without increasing the temperature of the absorbent, dividing the lean absorbent into i a plurality of bodies, recombining the two portions of the mixture, passing the mixture in series into intimate contact with first one body of absorbent and then with another, to separate the two constituents thereof, and returning the Y equalizing medium to the evaporating zone and the two bodies of enriched absorbent to the heating zone.

21. The process of producing refrigeration in a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a'pre'ssure equalizing medium, which comprises applying heat to,rich absorbent to liberate refrigerant, condensing the refrigerant, permitting the refrigerant to evaporate into an equalizing 76 medium to produce refrigeration, dividing a stream of deconcentrated absorbent into a pinrality of streams, passing the mixture formed in the evaporating zone in series and in counterflow to first one of said streams and then another, after first by-passing part of the mixture over the partially deconcentrated absorbent to liberate additional refrigerant, and returning the equalizing medium to the evaporating zone and the enriched absorbent to the heating zone whereby the above cycle may be repeated continuously.

22. The process of producing refrigeration in a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a pressure equalizing medium, which comprises applying heat to rich absorbent to liberate refrigerant, condensing the refrigerant, permitting the refrigerant to evaporate into an equalizing medium to produce refrigeration, passing part of the gaseous mixture so formed over the partially deconcentrated absorbent to liberate additional refrigerant, dividing a stream of the deconcentrated absorbent into two gravity actuated streams, passing all of the gaseous mixture in intimate contact with and in counterfiow to first one stream of absorbent to remove refrigerant therefrom, and then in intimate contact with and in counterflow to the other stream of absorbent to strip the remaining refrigerant from the mixture, dissipating the endothermic heat of absorption to a cooling medium, and returning the equalizing medium to the evaporating zone and the enriched absorbent to the heating zone in order that the process may be repeated continuously.

23. The process of producing refrigeration in a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a pressure equalizing medium which comprises applying heat to rich absorbent to liberate refrigerant, condensing the refrigerant, permitting the refrigerant to evaporate into an equalizing medium to produce refrigeration, by-passing part of the gaseous mixture so formed over the partially deconcentrated absorbent to liberate additional refrigerant, forcibly circulating the deconcentrated absorbent over a circuit having at least two parallel legs therein, forcibly circulating all of said gaseous mixture, including said by-passed portion, first into intimate contact with the absorbent in one of said legs, and then in intimate contact with the absorbent in another leg and then back to the evaporating zone.

24. The process of producing refrigeration in a closed absorption refrigeration system employing a refrigerant, an absorbent therefor, and a pressure equalizing medium, which comprises applying heat to rich absorbent to liberate refrigerant, condensingthe refrigerant, permitting the refrigerant to evaporate into an equalizing medium to produce refrigeration, by-passing part of the gaseous mixture so formed over the partially deconcentrated absorbent to liberate additional refrigerant, circulating the deconcentrated absorbent over a circuit having at least two legs therein, circulating all of said gaseous mixture including said by-passed portion in series and in intimate contact with the absorbent in one of said legs, and then in intimate contact with the absorbent in another leg, and then back to the evaporating zone, both of said fluids being circulated con-currently and forcibly circulated.

25. A compound boiler for use in an absorpheat directly to liquid in one section and indirectly to fluid in the other section, means operable to transfer liquid from the directly heated section to-the'other section, and means for circulating an inert gas through the indirectly heated section.

26. A compound boiler for use in an absorption refrigeration apparatus comprising a first liquid chamber and a second liquid chamber, means to directly heat one chamber, and to indirectly heat the other chamber, means operable to transfer partially deconcentrated liquid from said first chamber to said second chamber in response to the heating of one of said chambers, and means for circulating a gas through said second chamber.

27. A compound still for use in separating two liquids in solution having different boiling-points,

-comprising a first chamber and a second chamber, means for directly heating said first chamber and for heating said second chamber by heat not retained by the first chamber, a series of liquid dispersing members in the second chamber, means for transferring partially deconcentrated liquid from said first chamber to the liquid dispersing members in said second chamber, and means for passing an inert gas in intimate contact with the liquid in the secondchamber whereby the liquid is further deconcentrated.

28. A compound still for use in separating two liquids in solution having different boiling points, comprising a first liquid chamber, a flue having a portion thereof in heating relation to said chamber, a second chamber within said flue and positioned above said first chamber, heating means .at the lower end of the flue, means to transfer partially deconcentrated liquid from said first chamber to the second chamber, and means for passing an inert gas in intimate con- ,tact with the liquid in the second chamber whereby the concentration of the liquid is further reduced.

29. In an absorption refrigerating apparatus, a compound boiler system comprising a main boiler and an auxiliary boiler, means for causing the auxiliary boiler to operate -at a lower refrigerant pressure than said main boiler, and means for heating said boilers, said heating means including a heating source located near the main boiler and means for transferring heat from said source to said auxiliary boiler, the arrangement being such that said auxiliary boiler may operate at a lower temperature than said main boiler.

30. In an absorption refrigerating apparatus using inert gas, a compound boiler system comprising a main boiler, an auxiliary boiler, means using a single source of heat for heating said compound boiler, means for circulating the absorption liquid through said main boiler and said auxiliary boiler and means for circulating inert gas through said auxiliary boiler, the arrangement being such that a fluid, such as air, is

heated by said source of heat and passed first in I contact with said main boiler and then in contact with said auxiliary boiler, thereby heating both of said boilers.

CURTIS C. COONS.

CERTIFICATE .OF CORRECTION.

Patent No 2,178, 560n I November 7, 1959,

CURTIS C. COONS.

It is hereby certified that error appears in the printed specification r {the above numbered patent requiring correction as follows; Page 1, sec- 0nd column, line 55, for the word holder" read boiler; page 6, second column, line 67, claim 10, for "interemediate" read intermediate; page 7, first column, line 25, claim 12, before "by-passing" s t irst; and that the .said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the 'Patent Office,

Signed and sealed this 26th day of December, A. D, 1959.

. I Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

